Circulating tumor DNA (ctDNA) in peripheral blood is a “liquid biopsy” that contains representative tumor information including gene mutations. Additionally, repeated ctDNA samples can be easily obtained to monitor response to treatment and disease progression, which may be especially valuable to lung cancer patients with tumors that cannot be easily biopsied or removed. To investigate the changes in ctDNA after surgical tumor resection, tumor and blood samples obtained before and after surgery were collected prospectively from 41 non-small lung cancer (NSCLC) patients. Somatic driver mutations in tumor DNA (tDNA) and pre- and post-op plasma ctDNA sample pairs were identified by targeted sequencing in several genes including EGFR, KRAS, and TP53 with an overall study concordance of 78.1% and sensitivity and specificity of 69.2% and 93.3%, respectively. Importantly, the frequency of 91.7% of ctDNA mutations decreased after surgery and these changes were observed as little as 2 days post-op. Moreover, the presence of ctDNA had a higher positive predictive value than that of six tumor biomarkers in current clinical use. This study demonstrates the use of targeted sequencing to reliably identify ctDNA changes in response to treatment, indicating a potential utility of this approach in the clinical management of NSCLC.
A convenient and sensitive GC-MS method was developed to identify thirteen sesquiterpenes and polyacetylenes (e.g. caryophyllene, γ-elemene, α-caryophyllene, β-selinene, isoledene, germacrene B, elixene, atractylone, hinesol, β-eudesmol, atrctylodin, atractylenolide II and acetylatractylodinol) in Atractylodes lancea (Thunb.) DC., Asteraceae. Among those compounds, four major components including atractylone, hinesol, β-eudesmol and atrctylodin were quantified with standards; contents of other components were estimated by using calibration curve of hinesol. In this study, we presented that the concentrations of those thirteen components varied drastically in A. lancea samples from different producing areas. Among those components, atractylenolide II and acetylatractylodinol were identified by GC-MS for the first time. A hierarchical clustering analysis based on relative peak areas of those thirteen components in total ion current (TIC) profiles was used to characterize A. lancea samples from different producing areas. Further clustering analysis showed that a simplified method with only four major bioactive components could be used to serve the same aim.
Six novel 4,5-seco-rearranged abietane diterpenoids, including one tetracyclic diterpenoid, prionoid A (1), two tricyclic diterpenoids, prionoids B (2) and C (3), and three dicyclic diterpenoids, prionoids D (4), E (5), and F (6), were isolated from the roots of Salvia prionitis Hance (Labiatae). Their structures were elucidated using spectroscopic analysis. The structure of 1 was further confirmed by a single-crystal X-ray diffraction determination. Moreover, it was found that 4 (IC50 = 0.41 microM) and 5 (IC50 = 0.72 microM) showed significant cytotoxic activity against P-388 and A-549 cell lines, respectively.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.